Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32735 results found.

  1. GRB 240511A: Observations from GTC/OSIRIS+
  2. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  3. GRB 240516A: GOTO optical upper limit
  4. GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
  5. GRB 240511A: radio detection of afterglow candidate
  6. GRB 240514B: GOTO candidate optical counterpart
  7. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  8. GRB 240514B: GRBAlpha detection
  9. LIGO/Virgo/KAGRA S240514x: Updated Sky localization
  10. LIGO/Virgo/KAGRA S240515m: Identification of a GW compact binary merger candidate
  11. GRB 240514B: Fermi GBM Detection
  12. GRB 240513A: Fermi GBM observation
  13. LIGO/Virgo/KAGRA S240513ei: Updated Sky localization
  14. LIGO/Virgo/KAGRA S240514x: Identification of a GW compact binary merger candidate
  15. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate
  16. Fermi GRB 240514B: Global MASTER-Net observations report
  17. GRB 240513A: Tiled Swift observations
  18. GRB 240513A: Fermi-LAT detection
  19. LIGO/Virgo/KAGRA S240513ei: Identification of a GW compact binary merger candidate
  20. GRB 240511A: Fermi GBM Observation
  21. GRB 240511A: Swift-BAT refined analysis
  22. Fermi GRB 240513B: Global MASTER-Net observations report
  23. GRB 240511A: J-band observations with WINTER
  24. GRB 240511A : MITSuME Akeno optical upper limits
  25. LIGO/Virgo/KAGRA S240512r: Updated Sky localization and EM Bright Classification
  26. GRB 240511A: optical afterglow detection from the NOT
  27. LIGO/Virgo/KAGRA S240512r: Identification of a GW compact binary merger candidate
  28. Fermi GRB 240511A: Global MASTER-Net observations report
  29. Swift GRB 240511A: Global MASTER-Net observations report
  30. LIGO/Virgo/KAGRA S240511i: Updated Sky localization
  31. LIGO/Virgo/KAGRA S240511i: Identification of a GW compact binary merger candidate
  32. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  33. LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
  34. EP240506a: Xinglong optical upper limit
  35. EP240506a: CrAO ZTSH optical upper limit
  36. GRB 240504A: Fermi GBM Observation
  37. EP240506a: Archival radio searching
  38. EP240506a: TRT optical upper limit
  39. LIGO/Virgo/KAGRA S240507p: Updated Sky localization and EM Bright Classification
  40. EP240506a: Optical upper limit with Kinder observations
  41. IPN triangulation of GRB 240504A
  42. GRB 240502A: 1.3m DFOT Optical upper limit
  43. LIGO/Virgo/KAGRA S240507p: Identification of a GW compact binary merger candidate
  44. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  45. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfr and AT2024hfs
  46. LIGO/Virgo/KAGRA S240505av: Updated Sky localization and EM Bright Classification
  47. LIGO/Virgo/KAGRA S240505av: Identification of a GW compact binary merger candidate
  48. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  49. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  50. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  51. Fermi GRB 240504A: Global MASTER-Net observations report
  52. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  53. GRB 240502A: GOTO optical upper limit
  54. GRB 240502A: Fermi GBM Observation
  55. GRB 240415A 1.3m DFOT Optical upper limit
  56. GRB 240502C: GOTO possible optical counterpart candidates
  57. LIGO/Virgo/KAGRA S240501an: Updated Sky localization and EM Bright Classification
  58. LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
  59. Fermi GRB 240502B: Global MASTER-Net observations report
  60. Fermi GRB 240502A: Global MASTER-Net observations report
  61. GRB 240501B: GRBAlpha detection
  62. GRB 240430A: GRBAlpha detection
  63. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet Transient Candidates
  64. LIGO/Virgo/KAGRA S240422ed: Host redshifts of AT2024hfq, AT2024hfu, and AT2024hmo from DBSP
  65. Fermi GRB 240501A: Global MASTER-Net observations report
  66. GRB 240426A: VZLUSAT-2 detection
  67. GRB 240425A: VZLUSAT-2 detection
  68. MeerKAT Discovery of a Probable Radio Counterpart to EP240414a
  69. GRB 240408B: VZLUSAT-2 detection
  70. GRB 240407A: VZLUSAT-2 detection
  71. LIGO/Virgo/KAGRA S240501an: Identification of a GW compact binary merger candidate
  72. X-ray transient EP240414a: Detection of associated supernova
  73. LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
  74. LIGO/Virgo/KAGRA S240430ca: Identification of a GW compact binary merger candidate
  75. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  76. Additional DECam GW-MMADS Candidates from three nights of observations
  77. GRB 240425A: GRBAlpha detection
  78. Fermi-LAT gamma-ray observations of IceCube-240424A
  79. LIGO/Virgo/KAGRA S240426s: Updated Sky localization
  80. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limit for EP240426a
  81. LIGO/Virgo/KAGRA S240426dl: Updated Sky localization
  82. LIGO/Virgo/KAGRA S240428dr: Updated Sky localization
  83. LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet ToO observations
  84. LIGO/Virgo/KAGRA S240422ed: ENGRAVE VLT/XShooter spectroscopy of the host galaxy of J-GEM24a
  85. LIGO/Virgo/KAGRA S240428dr: Identification of a GW compact binary merger candidate
  86. Fermi GRB 240428A: Global MASTER-Net observations report
  87. LIGO/Virgo/KAGRA S240422ed: J-band non-detection of J-GEM24a
  88. LIGO/Virgo/KAGRA S240422ed: DDOTI Optical Upper Limit for J-GEM24a
  89. EP240426b: AST3-2 optical upper limit
  90. LIGO/Virgo/KAGRA S240422ed: Observations with 1.6m Mephisto
  91. LIGO/Virgo/KAGRA S240422ed: A transient discovered from Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
  92. LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
  93. LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
  94. EP240426b: EP-WXT detection of a new fast X-ray transient
  95. LIGO/Virgo/KAGRA S240422ed: Archival radio detection of EP240426a
  96. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfq, AT2024hfr, AT2024hfs, and AT2024hfx
  97. LIGO/Virgo/KAGRA S240422ed: GRANDMA Optical Upper Limits for EP240426a
  98. LIGO/VIRGO/KAGRA S240422ed: Historical variability for EP240426a
  99. EP240426a: YAHPT optical upper limit
  100. XMM-Newton observation of EP240426a

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov